Numerous situations exist in which a body cavity needs to be catheterized to achieve a desired medical goal. One relatively common situation is to provide nutritional solutions or medicines directly into the stomach or intestines. A stoma is formed in the stomach or intestinal wall and a catheter is placed through the stoma. This surgical opening and/or the procedure to create the opening is common referred to as “gastrostomy”. Feeding solutions can be injected through the catheter to provide nutrients directly to the stomach or intestines (known as enteral feeding). A variety of different catheters intended for enteral feeding have been developed over the years, including some having a “low profile” relative to the portion of the catheter which sits on a patient's skin, as well as those having the more traditional or non-low profile configuration. These percutaneous transconduit catheters (sometimes referred to as “percutaneous transconduit tubes”) are frequently referred to as “gastrostomy catheters”, “percutaneous gastrostomy catheters”, “PEG catheters” or “enteral feeding catheters”. U.S. Pat. No. 6,019,746 for a “Low Profile Balloon Feeding Device” issued to Picha et al. on Feb. 1, 2000, provides an example of one device.
The enteral feeding catheter serves as the pathway through the stoma for transconduit of feeding solution into the stomach or intestine. During feeding, the enteral feeding catheter must be connected to separate feeding tube that is associated with a pump that generates pressure to drive feeding solution from a reservoir through the feeding tube and into and through the enteral feeding catheter into the stomach or intestine. Feeding may take several hours and may occur at night while a patient is sleeping. Maintaining a robust and leak proof connection between the feeding tube and the enteral feeding catheter is important. It is also very desirable that the connection withstand twisting and pulling forces generated by movement of a patient.
However, a problem universal to low profile and non-low profile enteral feeding catheters is the difficulty in connecting and disconnecting the locking adapter of the feeding tube to and from the enteral feeding catheter base or head. Many prior art enteral feeding catheters, such as the one shown, for example, in cross-section in FIG. 1, have a low profile base B and a catheter C which extends through the base and a distance from the base. A distal end of the catheter of such a device/assembly often includes a balloon which may be expanded to hold the catheter in a position in a body lumen, such as a stomach lumen. Such an enteral feeding device/assembly also often has a plug “P” attached to the low profile or non-low profile device by a tether “T.”
Connecting a feeding tube to conventional enteral feeding catheters requires removing the plug P from the base to allow access to the feeding passage opening. Conventional enteral feeding catheters are designed with a base or “head” having a locking cap member fitting in the feeding passage opening. The locking cap member is configured to receive a conventional locking adapter connected to the end of a feeding tube. Generally speaking, these locking cap members have a keyway, a groove, a stop member and incorporate a slot to provide a design that is similar to the female portion of a bayonet fitting. A locking adapter has a dispensing projection and a key portion attached to that projection that fit into the locking adapter. The locking adapter is pushed into the locking cap member and twisted in place until it locks. Exemplary illustrations of these conventional features may be found in the above referenced U.S. Pat. No. 6,019,746.
Connecting, changing and/or disconnecting a feeding tube having a conventional locking adapter to/from a conventional enteral feeding catheter can be a surprisingly difficult exercise. If the patient is overweight, his or her size can limit visibility of the enteral feeding catheter base from the patient so that the patient has to maneuver the locking adapter in or out of the enteral feeding catheter base by touch or feel rather than by sight. If the patient has impaired motor skills, fitting a lock adapter in the locking cap member presents challenges during the positioning, pushing and twisting steps. If the patient is young, it is often necessary or desirable to change the assembly while the patient is sleeping. The turning on of a light during the night can wake the patient. Yet, without being sure that the new tube is correctly connected, there is a risk of the leaking of gastric contents onto a patient's skin surface, clothing, and the like. There is also a similar risk of the leaking of the feeding solution. Further, when the connector sits tightly within the base, it may be difficult to remove, thereby requiring extensive pulling, movement of the connector and base and even unwanted displacement of the base, all of which can cause leakage or irritate a sensitive stoma site.
Some conventional locking adapters are configured to allow partial twisting or rotation after the adapter has been locked in place. That is, after the locking adapter is twisted in the locked cap member so the key portion travels past a “detent”, the locking adapter can rotate between a position where the key portion contacts a stop and a position where the key portion contacts a detent. Unfortunately, the limited range of motion allows the conventional locking adapter to transmit twisting force to the enteral feeding catheter. This transfer of force may cause the catheter to twist or pull which can cause leakage or irritate a sensitive stoma site. If sufficient twisting force is inadvertently encountered, the key portion of the locking adapter may be forced past the detent as it would be when a patient or care give is disconnecting the locking adapter. After the key portion is forced past the detent, it can readily align with the slot/keyway thereby allowing the connector to inadvertently become completely disconnected. These conventional connectors have evident drawbacks that remain unresolved.
The popularity of low profile enteral feeding catheter heads or bases has also resulted in a low-profile conversion kit that provides a base or head component that is clamped onto a percutaneous transconduit catheter (i.e., only the tube) inserted through the abdominal wall using conventional endoscopic procedures or with a replacement percutaneous transconduit catheter (i.e., only the tube) that is inserted through a patient's stomach. Such a low-profile conversion kit is described in U.S. Pat. No. 5,549,657. According to that patent, base or head component has an anti-reflux valve assembly and a two-part clamp. After the base or head component is clamped on the end a percutaneous transconduit catheter, it functions as the base or head for the percutaneous transconduit catheter. The anti-reflux valve assembly includes a circular seat. A recess located beneath the seat is configured to receive opposed lips of a snap-fit feeding tube connector that snaps onto the circular seat. An example of such a low-profile conversion kit is commercially available as the Gaurderer Genie™ PEG System Kit available from Bard Nordic (Helsingborg, Sweden), a subsidiary of C.R. Bard Inc.
When a patient is ready to be fed, a snap-type feeding tube connector is snap fitted onto the anti-reflux valve assembly by pressing the snap-type feeding tube connector against the anti-reflux valve assembly to urge the lips of the feeding tube connector over the circular seat and into the recess located beneath the circular seat. When feeding is complete, the snap-type feeding tube connector is removed by prying or pulling on a set of opposed ears. Attachment and detachment of the feeding tube connector is facilitated by a set of opposed slots that enhances axial and radial distortion and flexure of snap-type connector when a force is applied to one or both of the opposed ears.
Connecting, changing and/or disconnecting a snap-type feeding tube connector to/from such a low-profile enteral feeding catheter head or base may also be a surprisingly difficult exercise at least for the same reasons as conventional locking adapter. Moreover, the application of force to press the snap-type feeding tube connector onto the head and also to pry it off the head transfers forces directly to the enteral feeding catheter which may create discomfort and cause irritation to the sensitive stoma site. The low-profile of the head and its relatively small size (e.g., typically between about 13 mm and 25 mm in diameter) also create difficulty in that opposed ears of the snap-type feeding tube connector can extend over the ends of the head and lie adjacent or even against the skin of the patient to make it difficult to grasp or pinch the ears between the fingers.
Accordingly, there is a need for a connector for coupling a medical fluid supply tube to the head of a catheter device having a circular hub. For example, there is a need for an enteral feeding extension set connector which permits a user or health care provider a way to easily connect and disconnect an extension set to the base of an enteral feeding tube. Such a system would permit a user or health care provider to easily and reliably disconnect the previous, used, feeding connector and connect a new feeding connector, desirably without needing to see the base.